After removing Wallpaper

We found that the plasterboard under the wallpaper has got a white plastic coating on it, very much like thin PTFE. When using steamer it peels in some areas, it will be impossible to remove completely. What is it and What do you sugest we can do to give us a good base to wallpaper ? It is a 1962 Bungalow. Many Thanks Pete.

AnswerIf it is a plastic then it should stand up to the moisture that's present whilst the plaster is drying. I've not come across this before so I would not like to give you advice - but if I was to do it I would be very thorough with the PVA. You could try applying a diluted PVA (50:50) to the whole area and then apply another coat of almost neat PVA that includes some sand that's been mixed in. Then when dry you have a very rough sandy surface that the plaster will be able to stick to. As the coat of PVA was fairly thick, this has effectively sealed the surface so that the moisture in the plaster should not cause any further peeling. But I do stress this is not advice but just a way that I would approach it. Let me know how you get on!